Yes, it's a direct drive but that makes absolutely no sense at all. The water level control has nothing to do with temperature selection. Sure your not talking about rinse cycle? Rinse cycle is cold water only.

With washer set for low load size and hot/cold temp and should be filling with hot water, check voltage at pink wire on water level pressure switch. If you have 120vac there but no water flow but does work when set to med load size, your washer is possessed

Yes, but that only closes when the hot water exceeds a certain temperature which then turns on cold water valve in addition to hot water valve already being on when hot is selected. A faulty bi-metal would not prevent hot water from working. There is no explanation to the problem you are having other than a possible low voltage problem at the pressure switch when low is selected but that doesn't make much sense either as adjusting the load size only controls the diaphram in the pressure switch. Checking the voltage at the pressure switch pink wire would confirm pressure switch is ok.

Eric

When hot wash is selected, timer contact 11 is closed, temp switch A and C are closed.